The DSPCA is advising pet owners not to put dogs in cars today.
The animal rights group is also advising people to keep pets in a cool place, with access to water.
Gillian Bird from the DSPCA said that animals should not be left in direct sunlight on hot days.
"Please, just don't bring your dogs in the car," she said.
"Even with all the windows open, the sun is blazing in and it can make your dog very, very sick.
"So the best thing, we're saying, is: leave your dogs at home, make sure they're in a nice, cool place, they have plenty of water, and they're not shut in a room where the sun is going to come blinding in."
ARAN (Animal Rights Action Network) also issued information for safeguarding animals in hot weather.
"Never exercise dogs by cycling and making them run alongside the bike or by taking them running with you," the group stated.
"Never leave an animal in a parked car in warm weather, even for short periods with the windows slightly open.
"A dog trapped inside a parked car can succumb to heatstroke within minutes – even when the car isn’t parked in direct sunlight."